As with travel to any foreign country, don't expect that the
over-the-counter medicines will be the same. Add to this some
fundamentally different Asian medical philosophies, and you've got quite a
gap. So if there are things you think you might need (even analgesics for
a headache, and regular toiletries) by all means bring them with you.
Prescription medicines, obviously, you should also take care of before you
go.

If necessary, there is an American medical clinic in downtown Tokyo, with English-speaking
doctors and familiar Western medicines. And in a true emergency, of course,
you'll need to interact with a Japanese hospital and doctors. GOH staff can
help if something bad happens. And the US organizers can try to run interference
as well.

There are neighborhood Police boxes (called "koban") all over the
place.
These are tiny structures, with just enough room, usually, for a desk and a
chair for the policeman on duty. The police staffing them often do not speak English, but are
still a fine place to go in the unlikely event that something untoward should happen.

Tokyo (and Japan in general) is prone to (usually small) earthquakes. If a
quake lasts more than a few shakes, leave the building - emergency exits
are marked with green signs. If you cannot leave the building, stay near a
doorway or interior structural wall.

Electricity

Japan runs on 100 volts, 50 Hertz (in Tokyo, anyway) so heating devices set
for American voltage may not get quite as hot as usual. (Don't forget
there should be a hotplate and pot in the mansion rooms.) Plugs are the
same as old-style American, i.e. non-polarized flat 2-prong plugs. Any
modern polarized American plugs will need an
adapter.

Trash

The Japanese burn much of their trash, so you'll need to separate trash
into burnable ("moeru") and non-burnable ("moenai") categories,
since those
go into different bins/areas. Basically, any paper- or wood-based trash is
burnable, and everything else is not. They are starting to do recycling of
some kinds of plastics, so that may be separated out as well. Trash areas
at the mansion will be noted, with the different kinds of trash separated
out.

Toilets

Sorry, I guess it was inevitable that the toilet discussion would happen.

Public restrooms in Japan do not, generally, have any kind of paper
products. You should bring a small pack of tissues for use as toilet
paper, and a pocket handkerchief to dry your hands off after washing. (Or,
like many Japanese, you can just shake your hands dry, a not-uncommon sight
outside of train station bathrooms.)

And as for styles of toilets - most public restrooms in the areas we'll be
in will have Western style toilets (or often a choice of Western or Japanese.)
Those of you with bad knees, never fear, the chances of having to use a Japanese-style
squat toilet are slim.